The main aim of of this thesis is to build up simple, an accurate and fast method forrnthe determination of fat and protein content in milk. Based on the laser scatteringrntheory, the ratio of the scattered light intensity to the transmitted light intensity,rnwhich is called scattered-transmitted method,is taken on as the optical parameterrncharacterizing the fat and protein content. In this way, the influence of the fluctuationrnof the power of the light source is reduced and the accuracy of determination isrnenhanced consequently. The method we used can be implemented in diary industriesrndue to its simple methodology and its economic importance because all milk productsrnare sold on basis of fat and protein content.Finally, the data analysis is carried outrnusing curve and surface fitting method. The fat contents of mama and shola homogenizedrnmilk types are determined to be 2.9% and 2.7%, respectively. The proteinrncontent of mama milk is 3.6% and for shola milk is 3.4%